AI + Logistics weakness

Yes definitely, though I'm sure they are aware and are just trying to tweak the priorities.

If war is declared AI should perhaps bump logistics up the list more than it currently does when threatened.  If a base level of weapons & defences have been researched (able to actually damage other ships) then logistics should be priority 1.

Someone noted a while back that if you look at custom races, by default logistics priority is near the bottom of the list. I might try a custom race with higher logistics priority and see if that fixes it.

You might want to even dig into the AI file itself if possible. I noticed that with some of the custom races that won the competition, logistics isn't even LISTED in the priorities. My custom races all tend to have logistics in the bottom 3-4 slots and they all seem to use it. I'm fighting a war right now around turn 120 and the faction I'm fighting which is custom has a logistics cap of 30 and they are using it.

(EDIT)

Ok, so I took a peak in the actual XML files, and here is what I am seeing. First, if you make a copy in game of say the Terrans and then look at the personality tab, you will see a list of priorities. They are in this order.

1. Expansion

2. Tech

3. Military.

4. Diplo.

5. Growth.

6. Wealth.

7. Fortification.

8. Influence.

9. Logistics.

Now, when you look in the XML, this is what we see.

<AICategoryWeight>
<Military>15</Military>
<Growth>10</Growth>
<Tech>20</Tech>
<Diplomacy>15</Diplomacy>
<Expansion>20</Expansion>
<Wealth>10</Wealth>
<Influence>5</Influence>
<Fortification>5</Fortification>
</AICategoryWeight>

If we order that, it corresponds with the list more or less. Expansion and Tech have the same value in this table. However, WHERE IS LOGISTICS? I'm about to test this out, I'm going to manually add Logistics to the table, resort the values based on the weighting scale of 100. Let's see if this change reflects the numbers in game!

(Edit) And we have a winner. This is precisely the problem. I just resorted the table adding Logistics to the XML file. I took 2 points from every value, which slotted Logistics in at a priority of 16, while tech and expansion had 18 points respectively. In game the position of logistics is now reflected as 3rd on the list. Functionally what does this mean? It seems to mean that the base factions have no logistics priority at all. In very long test games I haven't seen the base AI ever take logistics. Only races that have the organized trait take logistics. On the other hand, custom races with logistical priority seem to take logistics.

If you want the AI to take logistical tech until Stardock fixes it, you need to mod it or someone needs to mod it.

Ok, little update. I've been digging at this for a few hours now.

My first attempt to fix this was to give all the factions an AI priority with logistics. Then I discovered that each faction had AI plans which also ignored logistics as part of their priority.

So I modified both, adding logistics to the AI priorities. I ran two games to turn 100 and saw the same problem, custom factions tend to get logistics a little more than base factions do, but it's a total crap shoot.

So I dug a little more. Each race has their own technology strategy which is in racenamehereTechDefs.xml.

What it looks like, is that logistical techs are given weighting within the other priorities. So if the AI has a priority to do military research via a given AI strategy that it has loaded, it will look at the list of technology it can research and then weight those techs based on their own weightings. 

Here is an example.

<Tech>
<InternalName>ThalanInterstellarLogistics</InternalName>
<GenericName>InterstellarLogistics</GenericName>
<DisplayName>ThalanInterstellarLogistics_Name</DisplayName>
<TechTree>Thalan_Tree</TechTree>
<ShortDescription>ThalanInterstellarLogistics_ShortDec</ShortDescription>
<Description>ThalanInterstellarLogistics_Dec</Description>
<ColorDef>TechPurple</ColorDef>
<Icon>GC3_Intersteller_Craft_Icon.png</Icon>
<Bink>GC3_Interstellar_Craft_Temp.bk2</Bink>
<ResearchCost>60</ResearchCost>
<TechPoints>1</TechPoints>
<AICategoryWeight>
<Military>18</Military>
<Growth>14</Growth>
<Tech>8</Tech>
<Diplomacy>6</Diplomacy>
<Expansion>16</Expansion>
<Wealth>12</Wealth>
<Influence>10</Influence>
<Fortification>20</Fortification>
</AICategoryWeight>
<Stats>
<EffectType>LogisticsCap</EffectType>
<Target>
<TargetType>Faction</TargetType>
</Target>
<BonusType>Flat</BonusType>
<Value>10</Value>
</Stats>
<Prerequ>
<Techs>
<Option>OrbitalSpecialization1</Option>
<Option>OrbitalSpecialization2</Option>
<Option>OrbitalSpecialization3</Option>
</Techs>
<TechAge>
<Option>AgeOfExpansion</Option>
</TechAge>
</Prerequ>
</Tech>

So what we're seeing here, is that Fortification is the highest weighted value. This means that the AI is going to be looking at logistics when it is looking to fortify. Most races don't have much priority in fortification and aggressive races actually have AI plans which devalue fortification.

This is the problem I think. I'm going to edit the values in logistics to be more military based across the board and then later tonight or tomorrow I will report the findings.

Indeed custom factions tend to not have issues with logistics, I ran a test case, I cloned the Drengin, and when they came up against each other, base AI and custom AI, the custom one destroyed the base one purely because it was using logistics. Even though neither was any different, they were completely the same. 

So this would imply that a work around, would be to clone all the races for now and use them instead of the originals? Will test that tonight.

My base faction Drengin don't tend to have issues with logistics.

I believe the reason is this.

The AI has a set of AI strategies. The majority of them will not prioritize the proper techs until they are actually at war. There are a bunch of age of expansion strategies that tell the AI to basically avoid military research, and even the strategies for the aggressive AI like the Drengin, actually set fortification at a negative value (fortification is one of the primary weighted values for logistical research).

The weighted values that promote the AI to actually pick up logistics, occur when the AI is finally at war.

To account for what you saw in your cloned game, it's possible the cloned Drengin fought a war already. So they had had some time with those "at war" priorities which tell the AI to get logistics. It doesn't take a rocket scientist to see that if this is what is going on, it's kind of a massive problem for the AI. Since the player is going to get very easy initial wars. 

In any case i've gone through all the racial technology defines and changed the weighted values to be very heavy. Hopefully there is a little more research into logistics, if not before wars break out, then overwhelmingly as soon as they do break out. I've run a few tests and so far it seems like it's working.

The game I am testing with is at turn 93. The galaxy is at war and most of the factions have ZERO logistics researched despite being at war for 20-30+ turns already in some shape. Loaded up the game and within 21 turns everyone but the Iridium had basically maxed out their logistics for the current era. Everyone was in the 25-35 range which means they took the optional +5 Logistics and the first +10 logistics.

I guess I can simply give AI logistics. Well, actually sell it to everyone once I have it  .  The related point though is that AI (Yor in my game) despite being 2nd in production, didn't have any fleet to speak of... So logistics or no logistics, there was nothing for them to apply it to. 

The possible solution to this I see currently is not to prepare to wars. And start building military once already at war.  Declaring wars with no military to fight it feels a bit strange though ))

I believe this may be a deliberate 'feature' of the Krynn AI - Brad has referred to them as 'paper tigers' in at least one post.